1. Field of the Invention
The present invention relates to a signal processing apparatus, and more particularly, to an analog-to-digital converting apparatus for rapidly processing a plurality of analog input signals and a display device using the same.
2. Description of the Related Art
Typically, in order to convert a plurality of analog input signals to digital signals using an analog-to-digital converter (ADC) in a signal processing apparatus, an analog-to-digital converting apparatus as shown in FIG. 1 is used.
Referring to FIG. 1, a conventional analog-to-digital converting apparatus includes a multiplexer (MUX) 110, an ADC 120, and a microprocessor 130.
The MUX 110 receives multiple analog signals S1, S2, . . . , SN, and selects and outputs one of the input analog signals according to a switching control signal SEL generated by the microprocessor 130.
The ADC 120 converts the analog signal output by the MUX 110 to a digital signal and outputs it to the microprocessor 130.
The microprocessor 130 generates the switching control signal SEL and provides the SEL to a control terminal of the MUX 110 for controlling the MUX 110. The microprocessor 130 also uses the digital signals output by the ADC 120 in a predetermined control algorithm to produce some control values.
The analog-to-digital converting apparatus may be applied to an apparatus such as an apparatus for an automatic color coherence correction. In this case, the predetermined control algorithm corresponds to an automatic color coherence control algorithm, the multiple analog signals S1, S2, . . . , Sn SN, correspond to signals that are detected by photo-sensors (not shown) arranged over different positions on a screen, and the control values generated by the microprocessor 130 correspond to RGB color coherence correction gain values.
However, in the conventional apparatus, the MUX works according to a switching control signal SEL generated by the microprocessor 130, and so a data processing rate of the MUX is limited. Consequently, the sampling speed for input analog signals is also limited to an extent. More particularly, the increase in the number of a plurality of input analog signals input to the MUX 130 causes harmful effects on the data processing rate of the microprocessor 130. In addition, if the input analog signals are affected by any surrounding noise, such as an impulse noise, data processing results may be erroneous.